From The Perry Mason TV Show Book (Revised)
Murder as a three-ring circus. A famous clown named Felix is secretly married to a woman who is pretending to be married to the owner of the circus they both work for. When a struggle for control of the circus breaks out, the clown comes to Perry for advice.

Paul, Perry, and Della go to the circus and are surprised to see Lt. Tragg is also attending. (What are the odds?) During the performance the horrified onlookers see a clown shoot and kill one of the circus’s owners in the middle of the act, then run from the tent. When Felix is later charged with the murder, Perry has to figure out who was really in that clown suit.